There is option to buy Hardware Firewall, or something like this.
If you have big infrastructure you want to bring over to DO, or just want more information, Sales team will give you better info. You can contact them in Support Center.

DigitalOcean platform is very secure, but as DO offers un-managed servers, you’re on your own with security of server.
You can read 7 Security Measures to Protect Your Servers, it explains some of ways to protect server.

If you’re interested in physical location of servers, International certifications and standards, head over to DigitalOcean FAQ.

When setting up infrastructure, getting your applications up and running will often be your primary concern. However, making your applications to function correctly without addressing the security needs of your infrastructure could have devastating consequences down the...